Prior to World War I
there were many experimental
airmail flights made throughout the world.
The onset of the war, however, brought these to an end in
Europe as resources were applied to military needs.
World War I was the first opportunity for Europeans to exploit the
airplane.

However, at the end of
the war regular airmail
service trials began anew.
First, the Italians made an experimental flight between Rome
and Turin on May 22, 1917, after a postponement from May 17.
This led to the issue of the first airmail stamp, an overprint of a
special delivery stamp (Scott C1).
In June, 1917, the Italians also flew a hydroplane between
Naples and Palermo leading to the second airmail stamp.

Austria developed the
use of airplanes as
military couriers early in the war.
A military courier began flying with mail from Vienna to
Kiev in 1918
(as early as February 1 or possibly as late as March 20).*
German and Austrian army headquarters on the Eastern Front were located
in Kiev.

Military mail has a
three line cachet reading
"K.u.K. Fliegerkurierlinie | Wien-Kiev | Flugstation Krakau [or Lemberg
or Kiew]"
or a two line cachet "K.u.K. Fieldpost | Flugstation Krakau [or Lemberg
or Kiew]."

This courier service led
to the first sustained
civilian airpost service in central Europe.On flights
starting March 31, civilians
were permitted to use the service
between Vienna, Krakow, and Lemberg (now Lwow) en route to Kiev.The last
flight for civilian mail was on
October 15, 1918,
although military use appears to have continued later.*

The service used
military aircraft flown by
military officer-"observers."
A senior non-commissioned officer was also aboard to accept, handle,
and deliver the mailbags.

The flight from Vienna
to Krakow took four hours
including a half-hour stop enroute at Olmutz.
The flight took seven hours to reach Lemberg from Vienna.
Six more hours were required to get to Kiev with another en route stop
at Proskurov.

Mail was delivered and
picked up by the special
service
post offices using motor tricycles with armed escorts.
Since the flights left Vienna as early as 4:30 am, the
Vienna mail was generally cancelled the night before.

The inaugural eastbound
service was on March 31,
1918; however,
most of the first flight mail was cancelled on March 30.
184 covers were flown from Vienna to Krakow and 264 from Vienna to
Lemberg.

This cover flew on the
first westbound flight
from Krakow to Vienna, April 3.
There were only 81 covers on this leg of return flight.
There were 103 covers flown from Lemberg to Vienna.

The cover is
franked with new
airmail stamps issued on March 30.
The stamps were made by overprinting regular issues of 1916 with FLUGPOST.In
two cases the
stamps were also surcharged with new values.The 2k lilac
was surcharged with
1.50 K 1.50 and the 3 K ocher was surcharged
with 2.50 K 2.50 (Scott C1 and C2c - this copy of the 2.50 K is
perforated 12½x11½).
The 4k gray received only the FLUGPOST
overprint (Scott C3).

The first printing (consisting of 86,800, 85,900, and 84,900 pieces for
the 1.50 K, 2.50 K
and 4 K denominations, respectively) was printed on
light gray paper.
A second printing (110,900, 108,506, and 95,028 of the 1.50 K, 2.50 K
and 4 K, respectively)
on June 24 was on white paper.*

The rate for the airmail service was 1.50K for each 20 grams plus 1K
for special delivery service.
The airmail stamps on this cover came to 8K so it was
considerably overpaid and is most likely a souvenir or philatelic.
The airmail stamps could only be used for this service
and an additional stamp was required for regular postage.
The 1917 15h dull red Emperor Karl I (Scott 168) satisfied this
requirement.

The postal markings are all special airpost markings.
The stamps were cancelled with three strikes of a KRACAU 1 - KRAKOW 1
CDS.
There is also a Krakow FLUGPOST POCZTA LOTNICZA cachet CDS.
The cover was backstamped on its arrival in Vienna on the same day with
a FLUGPOST CDS.

Despite the short time available after the belated public announcement
of this flight on April 2, this cover has a preprinted address and
FLUGPOST.
The cover has a script marking "Erstflug Krakau Wien."
This may or may not have been on the cover when it flew.

Here is a postal card which was flown from Vienna to Lemberg
on April 12 just nine days after the first cover.

The card originated in, I believe, Vienna and was postmarked
with two May 11 CDS, the day prior to the flight.
It was also marked with the FLUGPOST WIEN -1 CDS at the airfield on
April 12.
There is a faint special CDS similar to the Krakow CDS above
for the card's arrival in Lemberg on the 12th.
The sender was

This card had a complete set of the airmails (Scott C1-C3) found on the
previous cover;
however, the card only required the 8h provided by the indicia for
regular postage.
Here is yet another card sent from Vienna to Lemberg on April 29.
It does not have the 4 k gray stamp.

It has two Vienna CDS as well as a Vienna FLUGPOST CDS.
It also has a Lemburg special receiver dated April 30.
The sender was Rudolf Friedl who, I think, was a prominent philatelist.

*Thanks to Paolo Bagaglia for the specifics of the printing numbers and
catching my Polish typo.
Thanks, too, to Knud-Erik Andersen for getting me to clarify the
relationship
of the start of the military courier service and opening its use to
civilian mail.

Editor's note: I am indebted to the fascinating book Pioneer Airpost Flights of the
World
1830-1935
by Dr. Max Kronstein, published by the American Air Mail Society
in 1978, for most of the preceding information.